package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;
import java.util.logging.Filter;

//文件上传和下载
@RestController
@Slf4j
@RequestMapping("common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    //文件上传
    @PostMapping("upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        log.info("文件上传:"+file.toString());

        //原始文件名称
        String originalFilename = file.getOriginalFilename();
        String substring = originalFilename.substring(originalFilename.lastIndexOf("."));

        //使用UUID查询生成文件名，防止重名
        String fileName = UUID.randomUUID().toString()+substring;

        //创建一个目录
        File dir = new File(basePath);
        //判断是否存在目录basepath
        if (!dir.exists()){
            //创建
            dir.mkdirs();
        }

        try {
            System.out.println(fileName);
            file.transferTo(new File(basePath+fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return R.success(fileName);
    }

    //文件下载
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){


        try {
            //输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));

            //通过输出流将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();

        } catch (Exception e) {
            e.printStackTrace();
        }

    }


}
